DVS (Dynamic Voltage Scaling) is known as a technique for realizing low power consumption of a semiconductor integrated circuit. The DVS is a technique for dynamically changing a voltage of a circuit block such as a processor according to a processing capability of the circuit block.
Currently, a general method of increasing an output voltage at the same slew rate at regular intervals is being used to digitally control an output slew rate of a DC/DC converter by DVS.
However, when starting up and shutting down the DC/DC converter to a high speed (for example, 40 mV/μsec or more), a rush current or an overshoot increases. Although a technique for controlling the slew rate is proposed in the related art, this technique cannot sufficiently reduce the rush current and the overshoot.